Minutes of the OGSA Data WG telcon, 14th September 2005.

0) Actions arising

- Dave to ask ADs to approve the streams BOF.
- Dave to mail Joel and Bill to suggest moving the data transfer BOF.
- Dave to propose dates to section authors for their review sessions.

- Everyone to talk with your contacts to get more participation in this WG
- Allen to write an overview section on security
- Section authors to add security notes to their sections

- Mario to ask an OGSA-DAI staff member to write something on the security issues around OGSA-DAI 
- Dave to revamp section 3 of the architecture document
- Allen/Dave to contact David Martin & Hiro Kishimoto to get reviewers & expert participation (after internal reviews).  

1) Early discussion

* Roll call 
Dave Berry, NeSC (Note taker)
Mark Morgan, University of Virginia
Allen Luniewski, IBM

* Apologies
Stephen Davey, NeSC
Mario Antonioletti, EPCC

The minutes were approved.

2) Action report 
      - Dave to contact more people about Personal Data services [Some Information about MyGrid is on the Web.  We could talk to them as a use case of the whole architecture - perhaps invite them to a telcon].
      - Dave to request that Bill's BOF at GGF15 precedes our main session [Done]
      - Dave/Allen to mail section authors re review telcons [Done; Dave to propose dates]
      - Dave to invite people to streams BOF/planning [Ongoing]
      - Dave to check access to phones from UK All-Hands Meeting [OBE]

      - Everyone to talk with your contacts to get more participation in this WG [Ongoing]
      - Allen to write an overview section on security [Ongoing]
      - Section authors to add security notes to their sections [Ongoing]

      - Mario to ask an OGSA-DAI staff member to write something on the security issues around OGSA-DAI [Ongoing]
      - Dave to revamp section 3 of the architecture document [Ongoing]
      - Allen/Dave to contact David Martin & Hiro Kishimoto to get reviewers & expert participation (after internal reviews).  

3) Planning the Data Streams BOF
Assuming our session request is granted, how shall we organise this session?
- Presentations?
- Preparation of a set of questions to address?
- More people to invite?

Action: Dave to ask ADs to approve the streams BOF.

Basic question: what do we mean by a stream?
- Case 1: a source of data that is intrinsically streamed, e.g. a sensor that is producing a continuous series of readings. 
- Case 2: a "pipe" created for a specific data transfer data from one source (which might be a file) to a sink.
What are the API differences?  You can't go forward and back on a sensor stream.  You can't write a stream.

ByteIO has two interfaces, but they don't correspond to the above distinction.  One interface is the unification of these two cases, analogous with "traditional" programming language libraries.  It includes properties for whether the client can set the position and whether the stream is writable.  The other interface is for reading a fixed-size data source where the position is held on the client.  Whereas the first (stream) interface requires session information, the second (random) interface is sessionless.

Questions that we want the BOF to resolve:
- What do we mean by a "data stream"?
- Grids have to consider attributes such as security, persistence, and quality of service. Do these raise any particular questions for streams?
- What are the important use cases?  Are there unusual or non-obvious cases that we need to consider?
- What is the natural programming model for streams in a distributed environment?
- How do we connect one stream to another?
- How do streams fit into a service-oriented architecture?
- The OGSA Data Architecture currently has sections on Provisioning, Querying, Replication, Caching, etc.  Do these apply to streams as well as static data?  Are there any particular aspects of streams that affect any of these sections?

We would like a 3-4 presenters, each to address some of these issues for 10-15 minutes.  The presentations will be followed with a discussion.

Action: Dave to invite people to attend.
4) Security Discussion
Issues arising from the write-up

Allen has started the draft.  He will continue to work on this.

5) Wrap up

The Data transfer BOF is tentatively scheduled for Sunday. 
Dave to mail Joel and Bill to suggest moving the data transfer BOF.

- 21st: Cancel
- 28th: Planning transfer session for GGF (Allen can't make it)
- 5th: GGF
- 12th: Review: Ann?
- 19th: Review: Peter?

Possible future topics: invite projects such as MyGrid to give us a presentation of their architectures.